The present invention relates to an improved process for rendering cellulosic containing materials more durably flame retardant without sacrificing the "hand" the fabric had prior to treatment with the flame retarding compositions. Further the invention relates to imparting flame retardant characteristic or property to easy care fabrics.
In the past the flame retarding treatment of a fabric with a processing sequence of application of tetrakis (hydroxy methyl) phosphonium hydroxide to the fabric and curing with ammonia resulted in initially flame retarding cellulose containing textile materials. This treatment, however, when applied to blends of cellulosic materials with synthetic fibers leaves much to be desired by way of durability to home washings. Nor does this sequence impart sufficient wash and wear properties to be of consumer interest. Accordingly, treatment of blended fabrics with this process has not enjoyed commercial success. When a cellulose blended fabric is treated with a formulation such as tetrakis (hydroxy methyl) phosphonium salt with urea and trimethylol melamine and is subsequently cured by the application of heat, durable flame retardancy is imparted to the fabric and the fabric has desirable wash and wear properties. Unfortunately however, the "hand" of the resulting fabric is highly undesirable, the fabric being very stiff and harsh to the users skin.
Applicant has found that through the process of the present invention, a desirable "hand" may be retained by the fabric while imparting thereto good wash and wear properties together with durable flame retardancy.
Various references teach the imparting of flame retardant characteristics to cellulosic materials such as U.S. Pat. No. 3,607,356 as well as U.S. Pat. No. 2,983,623. U.S. Pat. No. 3,421,923 describes a process of flame proofing cellulosic containing textiles, wherein the textile material is impregnated with an aminoplast and then impregnated in an aqueous bath containing tetrakis (hydroxy methyl) phosphonium chloride.
U.S. Pat. No. 3,684,559 teaches a method of rendering cellulosic fabrics fire resistant by the attachment to the fibers of a resinous product formed by the treatment of a product of reaction of anhydrous ammonia and a phosphoric acid anhydride. U.S. Pat. No. 3,685,974 teaches flame retardant compositions which are prepared by reacting phosphoryl chloride with ammonia in an aqueous system. U.S. Pat. No. 3,644,140 teaches a method for utilizing certain phosphonomide flame retardant compositions on cellulosic materials. U.S. Pat. No. 3,436,250 teaches a method of imparting flame resistance to cellulosic materials by treating them with an aqueous solution of a composition containing a condensed phosphoric acid and a tertiary amine. U.S. Pat. No. 3,819,580 teaches a method of imparting flame retardant characteristics to cellulosic materials employing soluble methylol phosphine adducts. U.S. Pat. No. 3,772,068 teaches a similar method wherein the solution contains a tetrakis (hydroxy methyl) phosphonium salt. U.S. Pat. No. 3,745,191 relates also to a similar process employing methylol phosphine adducts which contain halogen atoms attached to an aromatic carbon. Comparable processes are also taught in U.S. Pat. Nos. 3,791,854; 3,600,219; 3,681,124; 3,692,559 and 3,669,725.